Abstract: ball-and-seat has many problems used as the bottom valve of separated injection, separated profile control and pollution prevent strings, for example solid particle in the upper tube section has nowhere to deposit but stuck valve ball, which will directly resulted in measuring string invalid. In order to overcome the shortcomings, the distributary deposit down hole liquid inlet device is studied, which has facilities such as sideways incoming liquid, diffluent deposit channels, one-way ball spring centralizer. This device was characterized by the liquid inlet side tube, diffluent channels deposit and difficult being sanding in for ball valve. Combined with measuring string, the liquid inlet device can play many roles in many kinds of string, such as the sideways incoming liquid in grip string, inverse well flushing in the stratified injection pipe string and the solid depositing in the bottom profile controlling string or pollution prevention string. All of these improve the reliability of measure strings and enhance the adaptability of column to conditions of sanding and inclined shafts.